669872661 has 8 divisors (see below), whose sum is σ = 894033984. Its totient is φ = 446146560.

The previous prime is 669872657. The next prime is 669872663. The reversal of 669872661 is 166278966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 669872661 - 2² = 669872657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669872663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105196 + ... + 111381.

It is an arithmetic number, because the mean of its divisors is an integer number (111754248).

Almost surely, 2^669872661 is an apocalyptic number.

It is an amenable number.

669872661 is a deficient number, since it is larger than the sum of its proper divisors (224161323).

669872661 is a wasteful number, since it uses less digits than its factorization.

669872661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217611.

The product of its digits is 1306368, while the sum is 51.

The square root of 669872661 is about 25881.8983268229. The cubic root of 669872661 is about 874.9785729719.

The spelling of 669872661 in words is "six hundred sixty-nine million, eight hundred seventy-two thousand, six hundred sixty-one".